Google has launched an audacious attack on Microsoft, announcing laptop computers called Chromebooks that will use its own operating system – rather than Windows – will ship in June.

The machines will be made by Samsung and Acer, two companies that have previously made machines running Microsoft's software.

The laptops will coordinate tightly with Google's "cloud" online services, and have almost no capacity to store information. Instead, the bare-bones operating system is essentially a web browser that steers users to applications like email and spreadsheets directly on the web, rather than storing software such as Outlook or Word directly on PCs.

The move is Google's first directly onto Microsoft's home turf of PC operating systems and the Office suite software – a pair of monopolies that generate around $5bn of profits for the company every quarter. Until now it has largely avoided direct competition with Bill Gates's company on its strongest areas, focusing instead on internet areas such as search and webmail and online document services.

The Chromebooks shift day-to-day functions onto the internet, removing what Google sees as the time-consuming burden of tasks associated with traditional PCs such as installing software and updates, backing up files and running antivirus checks, executives said.

"The complexity of managing your computer is torturing users," Google co-founder Sergey Brin said at the announcement at Google's IO conference in San Francisco. "It's a flawed model fundamentally. Chromebooks are a new model that doesn't put the burden of managing your computer on yourself."

PC sales have grown steadily over the past 15 years, with brief dips during the recession, but there are signs of slowdowns, especially in Europe and the US, among consumers. Businesses are Microsoft's most loyal customers. Google is aiming at such "enterprise" customers, too, with the suggestion that their data will be safer in the cloud than on a PC that could get lost or stolen.

The company will offer businesses its Chromebooks, along with technical support, as a hassle-free solution for $28 a month. The laptops, using processors made by Intel, will be available for order initially in the US on Amazon.com and Best Buy's online store from 15 June.

As with Google's Android mobile operating system, the Chrome operating system (Chrome OS) will be free. The intention is that it will encourage people to spend more time on the internet – where they are more likely to use Google and so see or click on its adverts, because Google is the dominant provider of search adverts, with about 90% of world share.

In another move encouraging people to move their computing off their PCs and onto "the cloud", Google on Tuesday launched an online music locker service in the US letting users store and listen to their songs wherever they are.

The operating system and Chromebook PCs expand on Google's web browser, also called Chrome, that competes against Microsoft's Internet Explorer. Earlier on Wednesday Google announced that there are 160m users of its Chrome browser, launched in September 2008.